Clip for a sheet electrode

ABSTRACT

A clip for a sheet electrode, which is capable of easily and reliably pinching a sheet electrode, and capable of minimizing the number of parts, thus facilitating the assembling. This clip is constructed such that a movable plate ( 20 ) provided with slots ( 25 ) to be engaged with supporting axes ( 13 ) is engaged with a substrate ( 10 ) having the supporting axes ( 13 ), and a conductive leaf spring ( 30 ) which is bent in the near middle thereof is interposed between the substrate and movable plate so as to keep them in an opened state. After the insertion of a sheet electrode ( 50 ), the movable plate is pivoted against the force of the leaf spring so as to close and pinch the sheet electrode. When the movable plate is further shifted forward along the slots, the movable plate is fixingly engaged with the substrate, thereby maintaining the pinching of the sheet electrode.

FIELD OF THE INVENTION

The present invention relates to a clip for a sheet electrode useful forholding or pinching a sheet electrode which is designed to be adheredfor example onto the surface of a living body (skin) for picking upbioelectric signals from the living body so as to deliver thebioelectric signals to an external device for the purpose of preparingan electrocardiogram or electromyogram.

BACKGROUND OF THE INVENTION

In the measurement of bioelectric signals as in the case of preparing anelectrocardiogram, a sheet electrode comprising a sheet-like conductiveterminal having a conductive polymer gel layer attached to one surfacethereof is employed in such a manner that it is adhered through thepolymer gel layer onto a chest or other portions of an examinee atfirst, and after the conductive terminal of the sheet electrode ispinched with a clip, bioelectric signals from the examinee are picked upand delivered via a conductive wire connected with the clip to ameasuring apparatus for the evaluation.

As for the sheet electrode clip to be employed for the aforementionedpurpose, several kinds of the clip have been disclosed for instance inJapanese Utility Model Unexamined Publication H6-74103. As shown in thisutility model publication, so-called alligator clip which is usuallyemployed is accompanied with a problem that since the conductiveterminal of the sheet electrode is formed of a thin and slippery metalsheet, the clip is likely to be disengaged from the terminal while theterminal is pinched with the clip, thus leading to the generation oftrouble in the examination. When the force of spring is increased inorder to prevent the clip from being disengaged, the manipulability inthe engagement and disengagement of the clip would be deteriorated, thusinviting another problem.

In the light of these problems, there is proposed in the above-mentionedutility model publication an electrode clip having a protrusion at a tipend thereof, which is designed to be inserted into a through-hole formedat an end portion of the conductive terminal of sheet electrode. Thiselectrode clip is advantageous in that the sheet electrode can bereliably held by the clip as the through-hole to be engaged with theclip is formed at one end portion of the conductive terminal of sheetelectrode. However, this electrode clip is still accompanied with theproblems that it is troublesome in manufactural viewpoint to form athrough hole in the sheet electrode, and at the same time, since thesheet electrode is accompanied with an adhesive layer, it is difficultto completely remove the tailings of the punched hole.

Additionally, the urging force of the spring of the clip is set so as toalways close the tip end portion of the clip which pinches theconductive terminal of the sheet electrode. Therefore, it is required,at the occasion of employment, to maintain an opened state of the clipas opposed to the urging force of the spring, thereby enabling theconductive terminal portion to be inserted into the clip. In the lightof such an operation, it is not necessarily easy to insert theprotrusion formed on the clip into the through-hole formed at one endportion of the conductive terminal.

In any case, the conventional clips require not only a conductive memberto be connected with a conductive wire but also a spring member toprovide the clip with an urging force, thus necessitating a relativelylarge number of parts, and moreover, the assembling thereof is not easy.Further, since the conductive wire and the conductive member areintegrally molded through an insert molding, it would be difficult toexpect a high yield in the manufacture thereof and due to a high thermalstress in the manufacture thereof, it would be difficult to avoid themolded product from being easily broken.

The aforementioned utility model publication also discloses anotherembodiment of the electrode clip wherein a movable member is mounted ona substrate in such a way that it is enabled to slide in relative to andin parallel with the substrate, and the movable member is allowed, dueto the elasticity thereof, to move forward beyond a protrusion formed onthe substrate. Since a spring member for generating an urging force isnot employed in this embodiment, the number of parts can be reduced.However, it would be difficult to allow the movable member to smoothlymove along the surface of conductive terminal which is mounted on thesubstrate through an engagement between a through-hole formed in theconductive terminal and a protrusion formed on the substrate. Moreover,the conductive terminal may possibly be curled up due to the movement ofthe movable member.

BRIEF SUMMARY OF THE INVENTION

The present invention has been accomplished in view of theaforementioned problems, and therefore, an object of the presentinvention is to provide a clip for a sheet electrode, which is capableof easily pinching a sheet or film electrode (hereinafter referred to asa sheet electrode), capable of reliably pinching a sheet electrodewithout allowing the sheet electrode from being easily disengaged fromthe clip even if a conductive wire is pulled, capable of minimizing thenumber of parts so as to make the assembling thereof very simple, andcapable of being stably used for a long period of time.

With a view to realize the aforementioned object, the present inventionprovides a clip for a sheet electrode, which comprises a substrateprovided with supporting axes; a movable plate provided with slots whichare adapted to engage with the supporting axes respectively; a leafspring which is made of a conductive material, bent in the near middlethereof, i.e. U-shaped, interposed between the substrate and the movableplate, and connected with a conductive wire; wherein said leaf spring isalways urged such that the fore-end portion thereof is kept in an openstate; said movable plate is made pivotal in a direction to close theclip as opposed to the urging force of the leaf spring, thereby enablinga pair of distal ends of the leaf spring to contact with each other topinch the sheet electrode therebetween; and said movable plate isenabled to shift forward along the slots while rendering the sheetelectrode pinched between said pair of distal ends of the leaf springand to rest while being kept engaged with the substrate. The clip can bealso used for film electrode.

According to this clip for a sheet electrode, since the leaf spring isalways urged such that the fore-end portion of the clip which isdesigned to hold a conductive terminal of sheet electrode is always keptin an open state, the sheet electrode can be easily introduced into thepinching portion of the clip. After the introduction of the sheetelectrode into the pinching portion of the clip, the movable plate ispivoted in a downward direction as opposed to the urging force of theleaf spring, thereby enabling the conductive terminal of sheet electrodeto be pinched and fixed from top and bottom by a pair of distal ends ofthe leaf spring which is made of a conductive material. While keepingthis condition, the movable plate is then shifted forward so as toenable the movable plate to take a rested state mechanically. As aresult, it is possible to prevent the sheet electrode from beingdisengaged even if an external force is inadvertently applied to thesheet electrode. When the movable plate is kept maintained in thisstate, the fore-end portion of the movable plate acts to cause theconductive terminal of the sheet electrode to press-contact with thedistal end portion of the lower half of the leaf spring, therebyensuring a reliable electric contact between the leaf spring and theconductive terminal of the sheet electrode.

When the sheet electrode is to be removed from the clip, the movableplate is pulled rearward from the rested position thereof. As a result,the engagement between the substrate and the movable plate can be easilyreleased, and due to the force of the leaf spring, the movable plate isallowed to reliably return to the original opened state, thus allowingan easy removal of the sheet electrode.

According to this clip for a sheet electrode, since the leaf springemployed for giving an urging force is also functioned as a conductivemember, it is no more required to provide additional conductive memberfor making a connection with the conductive wire. Further, since theleaf spring can be integrally formed with the conductive wire throughfuse-bonding for instance, the resultant composite member being enabledto be assembled with the substrate, the number of parts can beminimized, thus facilitating the assembling thereof, and at the sametime, it becomes possible to prevent the assembled body from beingeasily destroyed.

According to a preferable embodiment of the present invention, themovable plate is enabled, while the slot thereof is kept engaged withthe supporting axes of the substrate, to pivot from the position wherethe fore-end portion of the movable plate is opened upward due to theurging force of the leaf spring to the position where the fore-endportion of the movable plate is further opened upward. Under thiscondition, the opened angle between the movable plate and the substratecan be enlarged, so that the assembling work such as the installation ofthe leaf spring onto the substrate can be facilitated.

According to a preferable embodiment of the present invention, theengagement between the movable plate and the substrate is effectedthrough an engagement between a protrusion formed on the substrate and acut-out groove formed in the movable plate. According to this mechanismof engagement, the manipulation to open and close the clip would becomeeasy and at the same time, the engagement and disengagement of the sheetelectrode can be reliably performed.

In a preferable embodiment of the present invention, both distal endportions of the leaf spring are provided with upright portionsrespectively, these upright portions being directed to face to eachother. More preferably, at least one of these upright portions isprovided at the tip end thereof with a large number of projected andrecessed portions. When upright portions are formed in this manner, theengaged state of the conductive terminal portion of the sheet electrodecan be further ensured, so that the sheet electrode can be reliablyprevented from being inadvertently disengaged during the measurementoperation using the sheet electrode.

According to another preferable embodiment of the present invention, thetip end portion of at least one of the halves of the leaf spring isprovided with upright portions having different heights, and the tip endportion of the other of the halves of the leaf spring is provided withan upright portion which is designed to be inserted between said uprightportions having different heights. When upright portions are formed inthis manner, the conductive terminal portion of the sheet electrode canbe pinched with said conductive terminal portion being bent accordingly.For example, the upright portion disposed on the movable plate side actsto push the conductive terminal portion of the sheet electrode into aninterval between a pair of said upright portions disposed on thesubstrate side, thereby ensuring an excellent contact state, and at thesame time, achieving a stable pinched and fixed state of said conductiveterminal portion.

In another preferable embodiment of the present invention, said leafspring is provided with a protruded portion for preventing theconductive terminal portion of the sheet electrode from excessivelyentering into the clip, thereby enabling the pinching position of thesheet electrode in the individual clip to be set to a fixed position,thus enabling to obtain a stable measurement value. By the way, thisprotruded portion may be formed perpendicular or be inclined rearward tothe inserting direction of the sheet electrode in relative to thesubstrate under the condition where the sheet electrode is being pinchedby the distal end portions of the leaf spring.

In another preferable embodiment of the present invention, said leafspring is provided, at the portion facing the substrate, with anopening, and said substrate is provided with a projected portion whichis designed to be engaged with the opening. When an opening and aprojected portion are formed in this manner, the engagement of the leafspring to the substrate can be further stabilized, so that the leafspring can be reliably prevented from being inadvertently disengagedfrom the substrate.

In a further preferable embodiment of the present invention, aconnecting portion between the leaf spring and the conductive wire iscovered with a heat-shrinkable resin. When this connecting portion iscovered with a heat-shrinkable resin, the stability of the connectingportion can be ensured, so that the connecting portion can be preventedfrom being inadvertently separated or from being exposed to a chemical.

By the way, the term“sheet electrode” employed in the present inventionshould be construed to include not only an electrode or an earthelectrode, which is designed to be adhered onto the surface of a livingbody (skin) for picking up bioelectric signals from the living body forthe purpose of preparing an electrocardiogram or electromyogram, butalso an electrode which can be employed for introducing, through a skin,an external electric signal (of low frequency, for instance) into theinterior of a living body or an electrode which can be employed in thegeneral industrial purpose. These electrodes generally comprise, as aninsulating substrate, a film of synthetic resin such as polyethyleneterephthalate (PET), polyethylene, polypropylene, polystyrene, polyvinylchloride, etc.; and an electric insulating material such as a syntheticpaper, unwoven fabric, etc. On this insulating substrate, an electrodeelement coated with a silver paste, a silver/silver chloride paste, acarbon paste, etc., or a conductive material such as a metal foil islaminated to act as a conductive terminal (electrode element). On theportions of these electrodes which are to be adhered onto a living body,a conductive material layer comprising a natural polymer type conductivematerial such as cross-linked karaya gum, or comprising a conductivepolymer gel such as sodium polyacrylate, polyacryl amide, etc. can belaminated.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is an exploded perspective view illustrating one embodiment of aclip for a sheet electrode according to the present invention;

FIG. 2A is a side view illustrating a state where the fore-end of theclip shown in FIG. 1 is opened;

FIG. 2B is a side view illustrating a state where the fore-end of theclip is further opened;

FIG. 3 is a perspective view illustrating a state where the fore-end ofthe clip is closed;

FIG. 4 is a perspective view illustrating a state where the fore-end ofthe clip is closed;

FIG. 5 is a cross-sectional view taken along the line V—V in FIG. 4;

FIG. 6 is a side view illustrating another embodiment of a clip for asheet electrode according to the present invention; and

FIG. 7 is a cross-sectional view showing a state where a sheet electrodeis pinched by the clip.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Preferred one embodiment of the clip for a sheet electrode according tothe present invention will be explained in details below with referenceto the attached drawings.

Referring to FIG. 1, the substrate 10 is an integrated molded productmade of a resin such as polyethylene terephthalate, polyamide andpolyacetal, wherein a fore region of a bottom plate 11 is formed of aflat plate, and a pair of right and left side walls 12 are erectedupward at a somewhat narrowed region located behind the aforementionedfore region. A pair of supporting axes 13 are externally and laterallyextended (in the direction orthogonally intersecting with thelongitudinal direction of the bottom plate 11) respectively from therear upper portions of the side walls 12. Preferably, the distancebetween the tip ends of the supporting axes 13 should be the same as thetraverse width of the fore flat plate region of the bottom plate 11.Further, a pair of projections 14 which are both laterally extendedrespectively from the fore upper portions of the side walls 12 andslightly inclined downward in the fore direction.

A passageway 15 having a cross-section is formed at the rear centralregion between the side walls 12, the passageway 15 extending in thelongitudinal direction of the bottom plate 11. This passageway 15 isextended rearward farther than the side walls 12, and a step portion 16is formed at each outer wall portion of the passageway 15. Further, arectangular projection 17 a is formed at the central portion of the foreflat plate region of the bottom plate 11. At the location behind therectangular projection 17 a, a pair of cylindrical projected portions 17b are projected, and the fore-end portion of the fore flat plate regionis formed into a raised bed portion 18. A plural number of ribs 19 eachextending transversely are formed on the bottom surface of the bottomplate 11 for the purpose of improving the manipulability thereof at theoccasion of manipulating it with one's finger.

A movable plate 20 is an integrated molded product made of a resin whichmay be the same as that of the substrate 10, and has a width which isthe same as that of the width of the fore flat plate region of thesubstrate 10. This movable plate 20 is constituted by an upper plate 21and a pair of side walls 22 extending downward respectively from theright and left rear side portions of the upper plate 21. The widthbetween the inner surfaces of the side walls 22 is approximately thesame with the width between the outer surfaces of the side walls 12 ofthe substrate 10. The fore portion of the upper plate 21 is slightlyinclined downward, thus forming an inclined surface 23. A plural numberof ribs 24 are also formed on the upper surface and/or the inclinedsurface 23 of the upper plate 21 for the purpose of improving themanipulability thereof.

A pair of slots 25 which are adapted to be engaged with the supportingaxes 13 formed on the side walls 12 of the substrate 10 are formed inthese right and left side walls 22. These slots 25 are inclined as awhole at the same angle as the inclined angle of the inclined surface23. Preferably, as shown in the drawings, these slots 25 should beconfigured such that the fore zone 25 a thereof is not inclined, theintermediate zone 25 b thereof is inclined, and the rear zone 25 cthereof is not inclined. Further, a pair of cut-out grooves 26 areformed at the fore-end portion of the right and left side walls 22, theangle of these cut-out grooves 26 being the same as the inclined angleof the inclined surface 23. These cut-out grooves 26 are adapted to beengaged with the projections 14 formed on the substrate 10. This movableplate 20 constructed as explained above is enabled, while these cut-outgrooves 26 being engaged with the projections 14 formed on the substrate10, to pivot from the posture thereof erected at an angle of about 90degrees as shown in FIG. 2B down to the posture thereof inclined almosthorizontally, thus contacting with the substrate 10.

A leaf spring 30 is bent in the near middle thereof, i.e. U-shaped, andis preferably formed of a single metal such as beryllium copper which isexcellent in conductivity, anti-corrosion and fatigue resistance.However, this leaf spring 30 may be formed of a stainless steel such asSUS 301 with a gold plating. As for the size of the leaf spring 30, itmay such that it can be entirely placed in the fore flat plate region ofthe bottom plate 11. The distal ends of the lower half and upper half ofthis leaf spring 30 are bent to form protrusions 31 a and 31 brespectively which face to each other. Further, according to thisembodiment, a large number of projected and recessed portions 32 a, 32 bare formed on the distal ends of these protrusions 31 a and 31 b.Additionally, a second protrusion 33 is cut and raised on the inner sideof the protrusion 31 a formed on the lower half of the leaf spring 30.According to this embodiment, under the condition where the leaf spring30 is closed as shown in FIG. 5, the protrusion 31 b formed on the upperhalf of the leaf spring 30 is designed to be inserted into a spacebetween the protrusion 31 a and the second protrusion 33.

A portion in the vicinity of the curved portion of the leaf spring 30 iscut out so as to form therein a terminal 34 which is to be connectedwith a conductive wire P. Further, a protruded portion 35 directeddownward is formed on the upper half of the leaf spring 30. The lengthof this protruded portion 35 should preferably be such that when theleaf spring 30 is closed as shown in FIG. 5, the protruded portion 35 isallowed to contact with the surface of the lower half of the leaf spring30. The lower half of the leaf spring 30 is further provided with a pairof engaging holes 36 which are adapted to be engaged with theprojections 17 b formed on the bottom plate 11 of the substrate 10. Arectangular opening 33 b formed as a result of the cutting to form thesecond protrusion 33 is designed to be engaged with the rectangularprojected portion 17 a formed at the central portion of the fore flatplate region of the bottom plate 11.

The reference number 40 represents a cover member to hold the conductivewire P, which is formed of an integral body made of a resin which may bethe same as that of the substrate 10. This cover member 40 comprises anupper plate 41 which is designed to cover the passageway 15 from the topthereof, and a pair of right and left side walls 42. A passageway 43 forholding the conductive wire P in collaboration with the inner surface ofthe passageway 15 is formed at the rear portion of the bottom surface ofthe upper plate 41. Moreover, a pair of engaging step portions 44 areformed on the inner wall portions of the right and left side walls 42 soas to be engaged with the step portions 16 formed on the outer wall ofthe extended portion of the passageway 15.

In the assembling of the clip for a sheet electrode which is constructedas mentioned above, the terminal 34 of the leaf spring 30 is connectedwith the conductive wire P at first, and preferably, after a covering 34a made of a heat-shrinkable resin is attached to this connected portion,the projection 17 a and the cylindrical projected portions 17 b formedon the substrate 10 are respectively allowed to engage with therectangular opening 33 b and engaging holes 36 formed in the lower halfof the leaf spring 30, thereby mounting the leaf spring 30 on thesubstrate 10. In this case, the length of the lower half of the leafspring 30 is set in advance to such that, under the above condition, theprotrusion 31 a formed on the lower half of the leaf spring 30 can bedisposed to nearly contact with the back surface of the raised bedportion 18 of substrate 10. Further, under this condition, theprotrusion 31 a and the bed portion 18 should be adjusted regardingtheir heights in such a manner that the upper end of the protrusion 31 ais disposed higher than the bed portion 18.

Then, the conductive wire P is allowed to rest in the passageway 15, andthe covering member 40 for holding the conductive wire is pushinglyplaced over the conductive wire P. Thereafter, the slots 25 of themovable plate 20 are allowed to engage with the supporting axes 13 ofthe substrate 10, thereby mounting the movable plate 20 in an uprightstate as shown in FIG. 2B, after which the movable plate 20 is pushedforward so as to make it pivot downward. As a result, the fore-end ofthe inclined surface 23 of the movable plate 20 is allowed to impingeupon the surface of upper half of the leaf spring 30. At this moment,due to the urging force of the leaf spring 30, the movable plate 20 ispushed up to take an obliquely raised posture. However, since themovement of the movable plate 20 is regulated by the configuration(locus) of the slots 25 and by the supporting axes 13, the postures ofthe movable plate 20 and the leaf spring 30 are balanced in a statewhere the supporting axes 13 are located at the fore zone 25 a of theslot 25 as shown in FIG. 2A. Namely, the movable plate 20 is maintainedin a posture where the fore pinching portion of the clip is opened.

When the sheet electrode 50 is to be pinched, the conductive terminalportion 51 of the sheet electrode 50 is introduced into the pinchingportion which is kept in an opened state. Thereafter, the movable plate20 is pushed downward as opposed to the urging force of the leaf spring30. As a result, the movable plate 20 is caused to pivot about thesupporting axes 13, and the protrusion 31 b formed on a fore-end portionof the upper half of the leaf spring 30 is caused to be inserted into aspace between the protrusion 31 a and the second protrusion 33 formed onthe lower half of the leaf spring 30. As a result, the conductiveterminal portion 51 can be reliably pinched by these projected portions.By the way, when the conductive terminal portion 51 is introduced intothe pinching portion of the clip, the fore-end of the conductiveterminal portion 51 is impinged against the protruded portion 35,thereby making it possible to easily positioning the sheet electrode 50at a predetermined position and to perform the measurement of largenumber of the clips under the same conditions.

After the conductive terminal portion 51 is pinched in this manner, themovable plate 20 is pushed forward (in the leftward direction in thedrawings) by means of one's finger tip. As a result, the movable plate20 is allowed to advance along the locus (shape) of the slots 25 formedin the side walls 22 of the movable plate 20. Thereafter, the movementof the movable plate 20 is stopped at the rear end zone 25 c. Duringthis advancing movement of the movable plate 20, the cut-out grooves 26are gradually brought to engage with the projections 14 formed on theside walls 12 of substrate 10, thus ultimately accomplishing a fullengagement between the projections 14 and the cut-out grooves 26 asshown in FIG. 3. As a result, the movable plate 20 is brought into afinally engaged state with respect to the substrate 10, so that even ifthe movable plate 20 is released from one's finger, the movable plate 20and the substrate 10 are kept in a state where the sheet electrode iskept pinched as shown in FIGS. 3, 4 and 5. Further, since the conductiveterminal 51 is pressed by means of the bottom surface of the movableplate 20 onto the protrusion 31 a formed on the lower half of the leafspring, it is possible to obtain an excellently contacted state of theconductive terminal 51, and at the same time, the sheet electrode can bereliably prevented from being inadvertently disengaged from this engagedstate. Preferably, as shown in FIG. 5, the size of the movable plate 20is adjusted to such that the distal end portion thereof is just placedon the raised bed portion 18 of the substrate 10 under this conductiveterminal-pinching condition.

In this embodiment, the slot 25 is inclined as a whole at an angle whichis almost the same as the inclined angle of the inclined surface 23 ofthe movable plate 20. Therefore, during the process wherein the movableplate 20 is shifted from the fore zone 25 a to the rear zone 25 c of theslot, an downwardly pressing force is generated by the inclined surface23 of the movable plate 20. Due to this downwardly pressing force, thepinching of the conductive terminal 51 between the protrusion 31 bformed on the upper half of the leaf spring 30 and the protrusion 31 aand second protrusion 33 formed on the lower half of the leaf spring canbe increasingly enhanced, so that the sheet electrode can be reliablyprevented from being inadvertently disengaged from this engaged state.When the inclined angle of the rear zone 25 c of the slot 25 is set toan angle which is parallel with or somewhat leftwardly raised angle inrelative to the surface of the substrate 10 under the condition wherethe sheet electrode is being pinched as shown in FIGS. 3, 4 and 5, theengagement of the movable plate 20 with the substrate 10 under theconductive terminal-pinching condition can be further stabilized.

When this pinched sheet electrode 50 is desired to be released from theclip, the movable plate 20 is pushed rearward (rightward direction inthe drawings) by means of one's finger. As a result, the movable plate20 is moved backward along the slot 25, and at the moment where theprojections 14 are disengaged from the cut-out grooves 26, the movableplate 20 is forced to pivot upward by the effect of the urging force ofthe leaf spring 30, and hence, the movable plate 20 is brought back tothe initial opened state. Under this condition, the sheet electrode 50can be easily removed. Further, when the movable plate 20 is furtherpivoted upward to take the posture as shown in FIG. 2B, the cleaning orrepair of the interior of the clip can be facilitated.

FIGS. 6 and 7 show another embodiment of the clip for a sheet electrodeaccording to the present invention. This clip differs from that shown inFIGS. 1 to 5 in the respects that the protruded portion 35 formed on theleaf spring 30 is somewhat inclined in the rearward direction, and thatthe slots 25 formed in the right and left side walls 22 of the movableplate 20 are wide V-shaped as a whole in configuration, so that the rearzone 25 c which is not inclined as shown in FIGS. 1 to 5 is absent fromthe slot 25. The constructions of other components are the same as thoseshown in FIGS. 1 to 5, so that the same parts are represented by thesame reference numerals, thus omitting the explanation thereof.

Since the protruded portion 35 is somewhat inclined in the rearwarddirection, the introduction of the distal end of the conductive terminal51 of the sheet electrode 50 can be further facilitated as the protrudedportion 35 can be acted as a guide, and moreover, since the distal endof the protruded portion 35 can be acted to press the conductiveterminal 51, the engagement of the sheet electrode 50 can be furtherstabilized. Additionally, since the slots 25 are wide V-shaped as awhole in configuration, the molding thereof can be further facilitated.

Although two kinds of projections 17 a and 17 b are formed on thesubstrate 10 for the purpose of stabilizing the attached posture of theleaf spring 30 in the embodiments shown in the drawings, one of them maybe omitted.

According to this clip for a sheet electrode of the present invention,since the pinching portion of the clip is always kept in an open state,the operation of inserting, pinching and disengaging the conductiveterminal of the sheet electrode can be greatly facilitated. Further,since the upper and lower members pinching the conductive terminal canbe kept in an engaged state not through an elastic force but throughmechanical means, it is possible to further ensure the pinching state ofthe conductive terminal and to prevent the conductive terminal frombeing inadvertently disengaged. Furthermore, since the leaf spring forkeeping the open state of the pinching portion all the time is alsoenabled to function as a conductive member to be connected with aconductive wire, in addition to the function thereof as a pinchingmember, it is possible to minimize the number of parts and to facilitatethe assembling thereof. Since the movable plate can be pivoted upward totake an upright posture, the cleaning or repair of the interior of theclip can be facilitated.

Further, since a conductive wire can be assembled in advance, throughfuse-bonding for instance, with the leaf spring functioning as aconductive terminal-pinching member, and the resultant composite isassembled with the substrate, the possibility of generating defectivescan be minimized as compared with the conventional structure where anelectrode-contacting member is to be insert-molded together with aconductive wire. Therefore, the clip according to the present inventionis more advantageous in an economical viewpoint. Furthermore, since theleaf spring and the conductive wire are subjected to a thermal stress ina reduced degree as compared with the conventional insert-moldedproduct, it is possible to employ the clip in a stabilized condition fora long period of time.

What is claimed is:
 1. A clip for a sheet electrode, which comprises; asubstrate provided with supporting axes; a movable plate provided withslots which are adapted to engage with the supporting axes respectively;a leaf spring which is made of a conductive material, bent in the nearmiddle thereof, i.e. U-shaped, interposed between the substrate and themovable plate, and connected with a conductive wire; wherein said leafspring is always urged such that the fore-end portion thereof is kept inan open state; said movable plate is made pivotal in a direction toclose the clip as opposed to the urging force of the leaf spring,thereby enabling a pair of distal ends of the leaf spring to contactwith each other to pinch the sheet electrode therebetween; and saidmovable plate is enabled to shift forward along the slots whilerendering the sheet electrode pinched between said pair of distal endsof the leaf spring and to rest while being kept engaged with thesubstrate.
 2. The clip for a sheet electrode according to claim 1,wherein said movable plate is enabled, while the slot thereof is keptengaged with the supporting axes of the substrate, to pivot from theposition where the fore-end portion of the movable plate is openedupward due to the urging force of the leaf spring to the position wherethe fore-end portion of the movable plate is further opened upward. 3.The clip for a sheet electrode according to claim 1 or 2, wherein theengagement between the movable plate and the substrate is effectedthrough an engagement between a protrusion formed on the substrate and acut-out groove formed in the movable plate.
 4. The clip for a sheetelectrode according to claim 1 or 2, wherein both distal end portions ofthe leaf spring are provided with upright portions respectively, theseupright portions being directed to face to each other.
 5. The clip for asheet electrode according to claim 4, wherein at least one of theseupright portions is provided at the tip end thereof with a large numberof projected and/or recessed portions.
 6. The clip for a sheet electrodeaccording to claim 4, wherein the tip end portion of at least one of thehalves of the leaf spring is provided with upright portions havingdifferent heights, and the tip end portion of the other of the halves ofthe leaf spring is provided with an upright portion which is designed tobe inserted between said upright portions having different heights. 7.The clip for a sheet electrode according to claim 1 or 2, wherein saidleaf spring is provided, at the portion facing the substrate, with anopening, and said substrate is provided with a projected portion whichis designed to be engaged with the opening.
 8. The clip for a sheetelectrode according to claim 1 or 2, wherein a connecting portionbetween the leaf spring and the conductive wire is covered with aheat-shrinkable resin.
 9. The clip for a sheet electrode according toclaim 1 or 2, wherein said leaf spring is provided with a protrudedportion for preventing the sheet electrode from excessively enteringinto the clip.
 10. The clip for a sheet electrode according to claim 9,wherein said protruded portion is inclined rearward to the insertingdirection of the sheet electrode.
 11. The clip for a sheet electrodeaccording to claim 1 or 2, wherein a plural number of ribs useful forpushing are formed on the bottom surface of the substrate and/or on thetop surface of the movable plate.